Today, telephone and communication connections of many kinds are commonly made using molded plastic modular connectors in standard shapes and sizes. Quite often there is a “family“ of connectors having a similar shape, but with different sizes, widths or numbers of electrical contacts. While a larger or wider plug connector cannot be incorrectly inserted into a smaller or narrower socket, the reverse is not always true. A smaller or narrower plug connector can often be incorrectly inserted into a larger or wider socket, and the expected connection and functioning will not occur, and electrical or mechanical damage may occur. What is desired is an electrical socket connector designed to prevent the improper insertion of smaller sized plug connectors.